Page end locking device for typewriter platens



July 18, 1950 P. J. CASEY 2,515,694

PAGE END LOCKING DEVICE FOR TYPEWRITER PLATENS Filed Oct. 23, 1947 ArroeME/S patented July 18, 1950 PAGE END LOCKING, DEVICE Fort TYPEWRITQEIR PLATENS Patrick J Casey, Washington, D. C. Application October 23, 1947, Serial No. 781,593 a 4 Claims. (Cl. 197-141) This invention relates to an attachment for typewriters, and more particularly to an attach ment for controlling the operation of the typewriter platen to determine with accuracy the width of the bottom margin of the typewritten An object of the invention is to provide a device ofthe character indicated which will accurately control a predetermined period of rotation for the typewriter platen by of which thenumber of typewritten lines on a page can be accurately limited.

,A further object of the invention is to provide a device of the character indicatedfin which the selective adjustment of the device for the limiting of'the platen movementto variable numbers of lines, is greatly simplifiedrand capable of accurate control by the operator.

, Various other objects will more particularly appear in the course of the following detailed description.

The invention consists in the novel construction, arrangement and combinations of parts hereinafter more particularly described and claimed. 7

One sheet of drawings largely diagrammatic, accompanies this specification as part thereof, in which like reference characters indicate like parts throughout.

In the drawings: 7 I T Figure l is a fragmentary perspective view of a portion of a typewriter showing the application thereto of the present invention;

"-Figure'2is a transverse vertical cross section taken substantially on line 2-2 of Figure 1;

I Figure 3 is an end view of a portion of the typewriter showing the application of the invention thereto, and Figure 4 is a detail perspective of the stoparm. -In the embodiment of the invention illustrated in the drawings, a typewriter frame is illustrated generally by Tfand the conventional typewriter platen by P. v

To control the number of rotations of the platen P and thereby the number of typewrittenlines on the page, gears II are associated with the ends of the platen P, which gears mesh with gears 3--3 formed on or secured to the ends of a fluted shaft 2, the endsof which are journaled in the platen carriage 35 parallel with the shaft of the platen. The fluted shaft 2 is co-extensive in length with the platen P and arranged parallel with and spaced therefrom.

The fluted shaft 2 is engaged with a gear 5 upon which it is slidable, the gear 5 being secured on a 2 shaft 4 extending transversely of 'thetypewriter frame and journaled thereon. One end of the shaft 4 carries a gear 6 which meshes with a gear I, which gear I is formed with an axially posi-' tioned internally fluted bore 3 adapted to slidably receive and meshwi'tha clutch gear 9 mounted on a shaft I0, one end of which is journaled on the typewriter frame. I I

; A disk I2 is provided formed with a plurality of circumferentially spaced transverse orifices adapted to receive a plurality'of transversely disposed headed pins .24. The disk I2 is further formed with axially disposed bosses I3 and- II. The boss I 4 is formed on its outer'end witha hand knob I5 by means of which the disk I2 can be rotated, ,while the boss I3 isformed with an axially disposed internally fluted bore I1 adapted to slidablyreceive and mesh with the clutch gear 9. The shaft I0 of the clutch gear 9 extends in axial alignment through the bosses I3 and I4 of the disk I2 and is formed on its outer end with a finger plunger I' I between which and the inner end of thebore I6 formed in boss I4 is disposed a compressionspring' 34 tending n'or mally to force shaft I ll and clutch gear 9' into the position illustrated'in Figure 2 in which it is in engagement with"and interlocks disk I2 with gear 1. It will be apparent that by pressure upon the plunger end II of shaft I0 the clutch gear S can be forced inwardly so as to disengage clutch gear 9 from-the flutedbore of disk I2, thus permitting the free rotation of disk I2 by means of the handknob I5 independently of gear 1; I 1

A second disk-20 formed with a second set of circumferentially spaced orifices complementary aligned circumferentially spaced holes provided in disks I2 and 20, the heads of these pinsbeing positioned outwardly with respect to disk 20 so that by withdrawingdisk 20 axially to the left with respect to disk I2, all of the headed pins are withdrawn a substantial distance. A journal 28 .is provided in the typewriter frameradially with respect to the axis ofthe disks and .gear I, and positioned so that a plunger 29 mounted therein is arranged to contact one of the headed pins in alignment therewith. The plunger 29 is formed on its outer end with a finger button 32 and is normally held in retracted position as by compression spring 33 positioned between the finger button 32 and the journal 28.

A stop 2? is rotatably mounted on the inner end of rod 26 and arranged in position to be engaged by any of the pins 24 which are projected sufficiently to engage therewith. The rod 26 is nonrotatably but slidably mounted in a journal 25 in the typewriter frame, and has formed or secured on its outer end a finger button 30 between which finger button 39 and the journal 25 is positioned a compression spring 3| adapted to normally maintain the rod 26 in its outward position, in which position the stop 21 is in proper alignment to engage the inner end of any of the pins 24 that has been projected its full length through the associated disks [2 and 20.

The rod 26 and stop 21 are resiliently connected 1 as by spring 40 and are further provided with intersecting pins 4| and 42 extending from said members respectively, whereby rotation of the platen in the normal .direction of feed is arrested by engagement of .a pin with this stop, but rotation of the platen in the opposite direction is per mitted to the extent of. a complete rotation of stop 31 on rod 25. I

In order to adjust the device without-reference to a particular sheet of paper; a window 31 is preferablycut from the end of the typewriter frame in position to expose to view one of the headed ends of the pins 24, and the said headed ends of said pins may be conventionally marked with suitable indicia to indicate lines or groups of lines advanced by rotation of the plate P.

To set the attachment to control the number of lines to be written on a particular sheet, the hand wheel 23 will, be drawn outwardly, thereby retracting all of the headed pins 24 to the maximum distance to the left, thereby withdrawing the inner ends of all of said pins from. the path of the stop 21. Thereafter, the disks 12. and 2!! can be rotated by hand wheel 15 until the head of the pin bearing the indicia indicating the "desired number of lines, appears through thewindow 31, at which point plunger '29 will be'forcedi inwardly by pressure upon finger: piece 32 .thereby projecting: the particular headed pin then inalignment withfsaid plunger to its full length, thereby bringing the end of that particular pin intothe oath of the stop 21. Thereafter. rotation of the platen P will transmit rotary motionto the fluted shaft 2 and through gear 5, shaft d, and gear 6, to gear I, which will in turn: transmit rotary motion through clutch gear 9 to disk l2=until the particular headed pin 24- which has been positioned by'plunger 29 comes in contactwith stop2l, which willlock the platen Pagainst further rotation.

If at this point it is desired to complete a sentence on that page, the operator can by depressing finger button 30 remove stop 21 momentarily while the additional line or lines are typed.

It will'thus be apparent that the platen will be accurately controlled yet with a possible flexibility as determined by the wishes of the operator.

Having thus described the invention, I claim:

1'. A control device for a typewriter platen comprising a gear mounted on the frame of the typewriter, means for transmitting rotary motion from the platen to said gear, a disk coaxially mounted with said gear and formed with a plurality of circumferentially spaced orifices, pins slidably positioned in said orifices parallel with the axis of the disk, clutch means associating the disk and gear, a stop positioned adjacent the disk and in a plane intersected by any pin projected sufficiently through the disk, means for simultaneously withdrawing all of the pins beyond the plane of the stop, and means for projecting a selected pin to intersect said plane.

2. The device of claim 1, with means for manually shifting the stop to a position clear of all of the pins.

3. The device of claim 1 in which the means for transmitting rotary motion from the platen to the principal gear includes a gear mounted at one end of the platen and coaxial therewith, a fluted shaft rotatably mounted in bearings carried by the platen carriage, said shaft arranged parallel with and spaced from the platen and in gear with. the gear carried by the platen, and arsecond gear mounted medially of'the typewriter frame in slidable and rotary engagement with the fluted shaft, said second gear mounted on a shaft geared to the principal gear.

4.. A typewriter platen control device comprising a gear having a fluted axial bore, means for transmitting rotary motion from the platen to said gear including a fluted shaft carried by the platen carriage parallel with the platen, said fluted shaft slidingly meshed with a gear mounted on a shaft carried by the typewriter frame, with gears connecting the platen with said fluted shaft and the second mentioned shaft with the first mentioned gear, a clutch gear slidingly mounted in the fluted axial bore of said first mentioned gear; a disk having oppositely disposed axial bosses and an axially disposed bore, said disk formed with a plurality of circumferentially spaced transverse orifices, the axial bore of said disk enlarged and internally fluted to-slidably receive the clutch gear in one boss, said clutch gear mountedon a shaft extending through said axial bore of the disk and journaled by one end on the typewriter frame, spring means normally biasing said shaft and clutch gear into a position interengaging both the first mentioned gear and said disk, a seconddisk formed with complementary transverse openings to those in the first disk, said second disk formed with an axial boss journaled exteriorly on the typewriter frame and rotatably mounted on-a boss of the'first mentioned disk, a spring :biased plunger slidably mounted. on the typewriter frame in alignment with the circumferentially spaced orifices insaid disks; headed pins passing through the orifices in said disks, and a spring biased stop member normally positioned in the path of the end of any of. said pins when said pin has been projected by said plunger the maximum extent "through said disks,

PATRICK J. C'ASEY.

I REFERENCES CITED The following references are of record in the file of this patent:

UNILED STATES PATENTS Corcoran Mar. 14, 1916 

